Into what sea does the River Nile flow? | Reference.com Into what sea does the River Nile flow? A: Quick Answer The River Nile drains into the Mediterranean Sea. It is the longest river on the African continent and in the world. Full Answer The headwaters of the Kagera River, known as its tributary Ruvubu, are the origination of the River Nile. From its origin, the river flows north through Africa before it enters Egypt. While many people believe that the majority of the River Nile is located in Egypt, only 22 percent of it is located there. It is believed that Ancient Egypt would not have existed without the River Nile as it provided the moisture that crops needed to survive. The Ancient Egyptians could only grow crops in the soil that formed after the River Nile flooded each year. Nile River | Longest River in the World | Aswan High Dam The Nile River The Nile River is the longest river in the world. It flows northward from the lakes of Central Africa to the Mediterranean Sea . However, the Nile carries less water than many other rivers because it flows through the Sahara desert in the north. 97% of Egypt’s population lives in the river’s valley.

Africa’s biggest river drains about 10 percent of the continent. It flows through many countries of eastern and northern Africa. The Nile consists of two tributaries. The White Nile starts near Lake Victoria and flows through steep canyons and mountainous landscapes of tropical Africa. The Blue Nile begins its journey on a high plateau in Ethiopia. It is shorter but carries more water and flows much faster than the White Nile. It also brings along fertile mud and causes most of the flooding in the north. The rivers got their names from the water that they carry with them. The Blue Nile starts out as a bright blue stream and turns black as it takes sediment with it. The White Nile carries whitish grey sediments from the tropical regions. The two rivers join at Khartoum in Sudan. From here the Nile River winds its way through northern Sudan and Egypt to the Mediterranean Sea. North of Cairo it spreads out into a delta and divides itself into separate channels. This area is made up of salty land and fertile soil. In the deserts between Khartoum and southern Egypt the Nile flows through a series of rapids called cataracts.

The Nile and Ancient Egypt Ancient Egypt could never have developed into one of the world’s greatest civilizations without the help of the Nile River. For centuries people bathed in the Nile, drank its water, told legends about it and built tombs and temples and even great pyramids near its banks. Farming in ancient Egypt depended on the Nile River. The year was divided into three seasons. The big floods came between June and September. From October to February farmers ploughed and planted crops in the fertile mud that came from the floods . They built ditches and canals so that the river’s water could spread to the crops. Harvest season was from March to May. The Aswan High Dam In the 1960s the Aswan High Dam was constructed near the border between Egypt and Sudan. Behind it the water of the Nile forms an artificial body of water called Lake Nasser. Because of the dam much of the mud that once spread across the Nile valley today gets caught in the lake. As a result farmers must use fertilizers to grow crops, but the good side is that irrigation can be controlled and farming can be done the whole year round. The dam also produces electricity for most of Egypt. Where is the Nile River?

| Reference.com Where is the Nile River? A: Quick Answer The Nile River flows from south of the equator northward through northeastern Africa and drains into the Mediterranean Sea. Measuring approximately 4,132 miles, the Nile is the longest river in the world. Full Answer The basin of the Nile includes Tanzania, Rwanda, Burundi, Kenya, Ethiopia, the Democratic Republic of the Congo, Uganda, South Sudan, Sudan and Egypt. The Nile is formed from three principal sources: the Blue Nile, the White Nile and the Atbara. The Nile supports the population living on its banks by providing water to a region that would otherwise be an inhospitable part of the Sahara desert. The Nile has been used to transport goods along its length for centuries. Managing water for peace in the Middle East 2.4 The Nile River Despite the great area of the Middle East, there are only three rivers, the Nile, the Euphrates, and the Tigris, that can be classified as large rivers by world standards. Of these, the Nile, which is the world's longest river, receives most of its discharge from precipitation falling well outside the Middle East on the upland plateau of East Africa and the highlands of Ethiopia (fig.

2.20). The Nile is the whole life of Egypt. The country owes its existence to the river, which provides water for agriculture, industry, and domestic use. Cultivation is dependent on irrigation from the river. Fig. 2.20 The Nile River basin The proposal to build a single large dam at Aswan for multiple objectives including flood control, year-to-year water storage, and hydro-power generation was put forward by Adrein Danionson in 1949 as an alternative to a "century storage" scheme. Construction of the high dam started in 1960 and was completed in 1970. Before the dam was built and went into operation, the Nile floods brought silt containing potassium and phosphorous but also could leach away any accumulated salts. The fine-grained alluvial soils of the Nile valley do not drain easily and need artificial drainage. Due to the hot, arid climate, irrigation water evaporates quickly, leaving behind its salt, causing salinization. The water levels in the Nile have been falling for nine years since the early 1980s.

In 1985-86 there was a three-metre drop in the level of Lake Nasser, the reservoir behind the Aswan dam, and in 1986-87 it fell from 195.6 m to 184.7 m (WPDC 1988). Egypt has been attempting to avert a national crisis by three strategies: rationalization, river development, and groundwater development. The reservoir storage has been recovered by steps with intensive rainfall and inflow in the early 1990s. This long-term fluctuation depends on the large-scale basin hydrology in the humid through the arid zones. 2.4.1 The river basin The Nile is 6,690 km long, extending through 35 degrees of latitude as it flows from south to north. Its basin covers approximately one-tenth of the African continent, with a catchment area of 3,007,000 kmï¿½, which is shared by eight countries: Egypt, Sudan, Ethiopia, Uganda, Kenya, Tanzania, Rwanda, and Zaire. Its main sources are found in Ethiopia and the countries around Lake Victoria.

All along the Nile's course from its most remote source, the Cagier River in Central Africa, to the Mediterranean, people are affected to some extent by the river or its water. With a few exceptions, the water resources in the headwater areas of the system are not yet much developed. The main development has taken place in the countries situated in the semi-arid and arid zones such as Sudan and Egypt. The upstream countries, however, are now considering Nile resourcedevelopment projects in their territories. The hydrographic and hydrological characteristics vary greatly over the basin. Rainfall in the headwater areas is abundant though seasonal. On the other hand, from about Sudan the river runs through arid country. The river system has two main sources of water: the Ethiopian highlands and the equatorial region around Lake Victoria. More than 60% of the river flow arriving in Egypt originates in the Ethiopian highlands by way of the Sobat, Blue Nile, and Atbara Rivers, with the bulk of this water coming down during the summer. The remainder of the flow arrives by way of the White Nile, which has its most remote source in Burundi.

This source is a tributary of the Kagera, which enters Lake Victoria near the border between Uganda and Tanzania. In the equatorial region, the Nile system consists of a number of great lakes, connected either by rocky sections or swamps. The White Nile, called Bahr el-Jebel after leaving the lake area, enters Sudan through rocky gorges and then flows through a large swamp area (the Sudd region) in southern Sudan, where it is joined by the Sobat from the east and the Bahr el-Ghazal, which occasionally receives water from Lake Chad from the west. In the Sudd region a huge quantity of water evaporates or is transpired from aquatic vegetation. Only a small part of the Bahr el-Ghazal flow ever reaches the Bahr el-Jebel, and practically all of its water disappears in the swamps. Although the contribution of the White Nile to the total annual flow at Aswan is only 30%, it is most important because of its timing: during the dry season from February to June its flow is large compared with that of the Blue Nile. 2.4.2 Hydrology The Nile flows for half of its course through country with no effective rainfall.

The rainfall of the Nile basin indeed is scanty compared with other major rivers in Africa such as the Zaire, Niger, and Orange Rivers. For the size of the Nile basin with its catchment area of 3,007,000 kmï¿½, the annual discharge is as small as 99.5 x 109 mï¿½, which is equivalent to 4.3% of the annual runoff. Rainfall is heavy in the headwater areas. The annual average rainfall in the lake plateau basin is about 750 mm (50 inches). The heaviest rainfall occurs at Kalungala on the island of Bugola, where it averages 2,250 mm (90 inches) per year. Other places of high rainfall are Bukoba on Lake Victoria and Gore in Ethiopia, where the average is about 2,000 mm (80 inches) per year. The distribution of rainfall is shown on the map in fig. 2.20. The dependence of Egypt on the Nile has led to intensive studies of quantities of water carried by the main stream and its tributaries throughout the year.

The long-term record of the annual flow discharge at Aswan from 1871 to 1965 is shown in fig. 2.21. The annual average for the 95 years is estimated to be 91.2 x 109 mï¿½, which was the basis of design for the year-toyear storage at the Aswan high dam. The change in the patterns of flow of the main Nile at Aswan and Rosetta before and after the construction of the Aswan dam are indicated in fig. 2.22. The upper graph in fig. 2.23 shows the average discharge of the main Nile at Aswan unaffected by reservoirs, the top line showing the discharge of the main river and other lines the component discharges. The peak discharge of 712 million mï¿½ per day, recorded on 8 September, was made up as follows: from the White Nile, 70 million mï¿½ (10%), from the Blue Nile, 485 million mï¿½ day (68%), from the Atbara, 157 million mï¿½ (22%).

The minimum discharge of about 45 million mï¿½ per day, on 10 May, was made up as follows: from the White Nile, 37.5 million mï¿½ (83%), from the Blue Nile, 7.5 million mï¿½ (17%), from the Atbara, none. During the high-flow stage from July to January, the largest proportion of the flows is contributed by the Blue Nile, and the least by the Atbara, while the White Nile is the more important source of supply during the low-flow stage from February to June. The Atbara carries much less water than the Blue Nile, but the effect of a peak may be considerable, owing to the shorter journey with very little damping. The Atbara contributes nothing from January to June. The average discharge of the main Nile at Khartoum and the portions contributed by the Blue and White Niles are shown in the middle graph in fig. 2.23. On average 84% of the water of the main Nile comes from Ethiopia and 16% from the lake plateau of Central Africa.

An interesting point is seen at the confluence of the Blue and White Niles: when the Blue Nile is rising rapidly, the White Nile discharge is ponded up and reduced, and only when the rise slows down does the White Nile discharge begin to increase. To make this clear a dotted line is interpolated showing the White Nile contribution as it would be if it were unaffected by the Blue Nile. When the Blue Nile falls, the White Nile discharge is increased by the water which has been ponded back. The effect of the Blue Nile is therefore to make a natural reservoir of the White Nile, and this effect is increased artificially on a great scale by the Gebel Aulia dam, which is situated about 45 km from Khartoum, some little distance up the White Nile. About 800 km upstream from Khartoum, the White Nile is joined by the Sobat, 90% of whose water comes from Ethiopia. About half the discharge of the White Nile comes from the Sobat and the other half from the Bahr elJebel through the swamps of the Sudd region.

The average discharge of the White Nile is about 28 x 109 mï¿½ per year, of which the Sobat produces 13.5 x 109 mï¿½, and the rest, except for a negligible amount contributed by the Bahr el-Ghazal, comes from the Bahr el-Jebel or its branch, the Bahr el-Zeraf. This remainder is shown as discharge from the swamps in the third graph in fig. 2.23. Because of the regulating effect of the large swamps of the Sudd region on the Bahr el-Jebel, the discharge of the latter varies very little throughout the year (see the bottom graph in fig. 2.23). When a rise occurs upstream, most of the water flows out of the river into the swamps, and only a very small part of the increase is felt in the stream below. When the river falls, there is a tendency for the marshes to drain back into the river, but large areas are below river level and cannot drain back.

The water that enters is lost by evaporation and by transpiration from the luxuriant vegetation, and in fact very little returns to the river, with the result that the Bahr el-Jebel loses nearly half its water in the swamps. The heavy evaporation and general dryness of the climate in Egypt and most of Sudan have various implications, including a substantial evaporation loss from the surface of large reservoirs. The evaporation loss from Lake Nasser (the Aswan high dam reservoir) is estimated to be about 10 x 109 mï¿½ per year, which is about 10% of the net storage volume of 90 x 109 mï¿½. In Egypt evaporation is at a maximum in June and a minimum in December and January. In northern Sudan it is the same, but May has practically the same evaporation as June. In the vicinity of Khartoum the maximum is in April and May, owing to the reduction later caused by monsoon rains, of which this area is on the fringe. In southern Sudan the minimum evaporation is in the months of July and August, at the height of the rains.

The evaporation in Egypt and Sudan, on the whole, follows the temperature. Potential evaporation at selected points in the Nile basin is shown in table 2.2 and the estimated monthly evaporation from Lake Nasser in fig. 2.24. Table 2.2 Mean daily potential evaporation at selected points in the Nile basin Fig. 2.24 Monthly evaporation rates for Lake Nasser (Source: Hurst 1952) 2.4.3 Water-resource development of the Nile system The national-economy and social objectives of developing Nile resources may vary from country to country. Certain Nile projects in the upper parts of the basin could be also advantageous for the more downstream countries. The timing of such projects could have a significant effect on the development of the resources of the basin as a whole The Nile is a geographical unit, and projects for its full development must also form a unity, the parts of which must work together. The basic idea of a 1950s scheme, an account of which follows, was year-to-year storage, or "century storage" in Hurst's (1952) terminology.

The key projects in Hurst's master plan were the Owen Falls dam, Lake Kioga barrage, Lake Albert dam, Jonglei diversion canal, Lake Tana dam, Fourth Cataract dam, Aswan high dam, and Wadi Rayan reservoir (see table 2.3). The hydraulic works in the Nile basin are shown on the map in fig. 2.25. Table 2.3 Existing dams the Nile basin Dam a. Outflow regulation with lake storage, or run of the river. b. Net. c. Barrage for irrigation intake. A major step in achieving collaboration among the Nile basin states was initiated in 1967 when the five countries Kenya, Tanzania, Uganda, Sudan, and Egypt started a hydro-meteorological survey of the basins of Lakes Victoria, Kyoga, and Albert, with the assistance of the UN Development Programme. Fig. 2.25 Hydraulic works of the Nile basin (Source: Beaumont et al. 1988) 2.4.4 Jonglei diversion canal project The Jonglei canal scheme to divert water from the Bahr el-Jebel above the Sudd region to a point farther down the White Nile, bypassing the swamps (see fig.

2.25), first studied by the government of Sudan in 1946, would make significantly more water available for use downstream. Plans were developed in 1954-59, and work on the project began in the 1970s, but it has been held up for many years by political instability in Sudan (Collins 1988). The original plans could now be reviewed, taking into account the completion in 1970 of the Aswan high dam, with its gross storage capacity of 168.9 x 109 mï¿½ and maximum spillway capacity of 11,000 mï¿½/sec, and our present increased knowledge of the hydrology of the Blue Nile and the hydrometeorology of the Albert-Victoria catchment. The water from the southwestern tributaries (the Bahr el-Ghazal system) for all practical purposes does not reach the main river and is lost through evaporation and transpiration in the swamps. It should be possible to reduce these losses and to lead at least a part of the water to the main river.

This procedure would require international collaboration, because storage and regulation would become necessary in Lake Albert to reduce flood levels in Sudan. Furtherrnore, storage would probably be needed on the Blue Nile in Ethiopia because the reservoir of the Aswan high dam by itself would not be large enough to regulate the combined floods of the Bahr el Ghazal, Bahr el-Jebel, and Blue Nile. It is estimated that the Jonglei canal project would produce 4.8 x 109 mï¿½ of water per year, including 2.4 x 109 mï¿½ for the first-stage project and 2.4 x 109 mï¿½ for the second-stage project. There are, however, complex environmental and social issues involved, which may limit the scope of the project in practical terms. 2.4.5 Hydro-power potential The hydro-potential of the Nile system is enormous, but the energy demand in the Nile basin countries is still small at present, with the exception of Egypt.

According to the Ministry of Information of Ethiopia in 1966, the hydropotential of the whole Nile system was preliminarily estimated to be about 8,000 MW (Deekker 1972). The most promising river for hydroelectric power development is the Victoria Nile, of which the hydro-potential is preliminarily estimated to be 1,843 MW in total, including six potential stations such as Bujagali (180 MW), Busowoko (150 MW), Kalagala (125 MW), Kamdinia (234 MW), Aingo (490 MW), and Murchison (664 MW) (Deekker 1972). 2.4.6 The Aswan high dam The importance of energy production at the Aswan high dam to the Egyptian economy is perhaps about equal to that of making more water available for irrigation, taking into account the huge saving in crude oil for energy production. The construction of the Aswan high dam has affected the entire economy of Egypt, allowing reliable irrigation throughout the year and satisfying about 40% or less of the country's energy demands.

The flow of the Nile River below the Aswan high dam is fully regulated. Releases from the dam are authorized by the Ministry of Irrigation and are based on seasonal irrigation needs in the Nile delta. The nature of Egypt's climate, as well as the established cropping patterns, require a very high release in the summer months when agricultural production is at its peak. Monthly irrigation release requirements are shown in table 2.4. Hydro-power generation at the dam has always been viewed as a residual benefit since the potential varies extensively between summer and winter months because of the uneven distribution of downstream irrigation requirements. Egypt's irrigation practices require nearly 55 x 109 mï¿½ of water from the Nile every year, which is the amount allotted to Egypt by the 1959 Nile Waters Agreement with Sudan. Sudan was allotted 18.5 x 109 mï¿½ by the same agreement but has been using only 16.5 x 109 mï¿½ per year in the 1970s. Monthly flows at various points along the Nile River have been recorded since the late 1800s.

From 1871 to 1976 the flow records at Station Aswan were adjusted to account for Sudanese abstractions and evaporation losses. The water stored in the upper rule storage zone is considered to be live storage and can be released to meet irrigation demands or to prevent flooding. Reservoir storage is discretized into 18 states, varying from a maximum of 168.9 x 109 mï¿½ (183-m elevation) to 89.2 x 109 mï¿½ (168-m elevation). According to an inventory of the world's hydro-power in 1989, the power station at Aswan has a rated capacity of 1,815 MW with an installed capacity of 2,100 MW, which accounts for about 40% of the national power supply (Mermel 1989).

Table 2.4 Monthly irrigation release requirements (109 mï¿½) from the Aswan high dam Jan Source: Thomoson and Marks 1982 2.4.7 Waterlogging and salinization problems of the Nile delta Before the implementation of year-to-year storage at the Aswan high dam, the Nile floods brought silt to the fields of Egypt containing potassium and phosphorous and could also leach away accumulated salts. The fine-grained alluvial soils of the Nile valley do not drain easily and need artificial drainage. Because of the hot-arid climate, irrigation water evaporates quickly, leaving behind salt which causes primary salinization. Consequently, farmers had to apply more water to wash the accumulated salts into the ground below the root zone. Deep percolation thus caused a rise in the water table to a few decimetres below the surface level soon after the change to perennial irrigation. The soil then became waterlogged. When the water table is less than two metres deep, capillary forces lift it to the surface, where the salts accumulate after evaporation. This is known as secondary salinization.

Thus, to avoid primary salinization it is essential to ensure quick infiltration of irrigated water, and to avoid secondary salinization the water table must be kept low. In 1982 almost all the irrigated area in Egypt was potentially affected by salt, and at least half of the area (12,000 kmï¿½) is already more or less affected. Egypt's agriculture potential and Nile delta salinity are mapped in figs. 2.26 and 2.27. About 400 kmï¿½ are provided with drainage systems each year at a cost of US$200 per hectare. Nevertheless, this is not sufficient to stop salinization. Farmers are unwilling to make this investment, and the government authorities have difficulty in keeping open the drainage channels that are essential for proper functioning of the tile drainage underneath the farmlands (Meybeck et al. 1989; Beaumont et al. 1988). Regulating the flow of the Nile at the Aswan high dam has immensely increased the costs of agriculture for the irrigated lands on the Nile delta by requiring artificial fertilization, drainage systems, and water lifting.

On the other hand, some costs have been reduced, such as those for clearing the irrigation channels of silt. 2.4.8 Egypt's water crisis and the Aswan high dam Until high flows on the Blue Nile in 1990 saved the situation, Egypt was facing a national crisis as a result of nine years of falling water levels in the. Nile. and Lake Nasser Countermeasures taken to avert the water crisis comprised the following three strategies (WPDC 1988): >> rationalization - improving irrigation systems to save 86 million mï¿½ of water per year, and recycling agricultural drainage to recover 196 million mï¿½ of water per year; >> river development - building a major new dam on the Nile at Rashid, near Alexandria, to reduce the Nile's flow into the Mediterranean; Fig. 2.27 Nile delta salinity (map area indicated by box in fig. 2.26) (Source: Ab-Zeid and Biswas 1990) >> groundwater development - exploiting underground reservoirs to develop nonrenewable groundwater in the deep sandstone aquifers.

Details of the groundwater development plan for the deep sandstone aquifers in the New Valley are given in section 2.7.4. Lesson 4: The Nile River - An Overview Lesson 4: The Nile River - An Overview The Nile Delta What is a delta? We know that the Nile delta gave its shape to the Greek letter Δ, but the Nile is not the only river in the world that has such an elegant delta. To geologist, "delta" is the name given a body of sediment deposited at the mouth of a river where it flows into a standing body of water. Deltas form through a very simple process: fast-moving water can carry lots of sediment (sand, clay, mud and even rocks) but these heavy particles settle to the bottom rapidly when the water stops flowing. As rivers enter the sea, or even a large lake, the river velocity slows down markedly, and the sediment that was traveling downstream stops moving and falls to the bottom. The eventual shape of a delta is formed by the action of waves, tides and the stream itself. When the river is large, it can carry a lot of sediment and thereby form a large delta.

In such cases the main flow splits into two or more distributaries, smaller streams that traverse the growing delta. We see this pattern in the Nile as well as in our own Mississippi River delta. In fact, the Nile and Mississippi deltas are very similar in size and shape. Images of the Nile Delta (left) and Mississippi Delta (right). Source: Copyright 2002 Tasa Graphic Arts, Inc. Let's take a moment to talk about how deltas form and grow. Like the Nile, the Mississippi River carries a tremendous amount of sediment. Why? These rivers drain huge tracts of land - dirt from the majority of the US is carried by the rain into the river and down the Mississippi River towards the Gulf of Mexico. Drainage Basin of the Mississippi River. Source: Plummer/McGeary/Carlson Physical Geology, 8th edition, Copyright 1999, McGraw-Hill Companies, Inc. All Rights Reserved. One big difference between the two is that while the Nile delta is shrinking (the Mediterranean Sea is eating away more sediment than the river can supply), the Mississippi delta is growing. The image below shows the growth of the Mississippi delta over the past 10,000 years.

Each of the numbered, colored lobes represents a portion of the delta that grew for a period - until the pile of sediment grew too large and the river needed to find a new course. Look closely at lobe 1, where the Atchafalaya River runs into the Gulf of Mexico. The Mississippi River would like to flow through this distributary, but the powers of commerce and control maintain the current river channel. The cost of this effort is tremendous, and as the effects of Hurricane Katrina have shown, maintaining a river with levees is not always easy. Mississippi River delta growth over time. Source: Copyright 2002 Tasa Graphic Arts, Inc. What does a delta look like inside? The image below shows a cut-away view of a growing delta. As the delta pushes out into the sea, or progrades, successive pulses of sand-sized sediment create the tilted foreset beds, while the smaller particles (which travel farthest) form the horizontal bottomset beds. As the sediment pile grows, the river distributaries must change course (remember, they cannot flow uphill) and in so doing generate new lobes for the delta.

Cut-away view of a growing delta Source: Copyright 2002 Tasa Graphic Arts, Inc. Note: Please click on the image to see a larger version. As a result, the delta itself is an environment of physical change. Over human time scales, one can expect the location and flow regime of distributaries to change as the sediments thicken. Deltas are also subject to severe erosion and flooding by unusually high tides and storms. Worse yet, delta soils dewater and compact over time causing the ground level to sink relative to sea level. Extensive construction and pumping of groundwater for domestic or industrial use both compound this problem, and as a result the major delta cities of the globe are in trouble. New Orleans, Venice, Shanghai, and Bangkok are all examples of delta cities that are losing the long-term battle between land and sea. What about the Nile delta? We look next at examples of ancient cities built upon the Nile delta that have vanished from view entirely: Heralkeion, Menouthis and Eastern Canopus.

We know a lot about these cities from the legends and myths of the ancient Greeks, but it wasn't until 1999-2000 that a group of French marine archaeologists found well-preserved evidence of them on the floor of the Mediterranean Sea. Herakleion and Canopus were built at the mouth of the Nile, along the outlets of the Canoptic distributary of the Nile. They were established as centers for commerce and navigation, and were the primary gateways to the Nile and all of Egypt from the 1st through 6th centuries AD. All ship traffic entering the Nile River from the Mediterranean paid taxes in Herakleion. To the east, the town of Menouthis - likely a part of the larger city of Canopus - was the site of a temple to the goddess Isis, and became a destination for religious pilgrims as well as extravagant religious festivals. Canopus distributary Source: Submergence of Ancient Greek Cities Off Egypt's Nile Delta — A Cautionary Tale Although the cities had easy access to fresh water and the Mediterranean Sea, they were unprotected against the effects of flooding, earthquakes and ground subsidence.

Both of these cities now lie submerged to a depth of 5-7 meters beneath the waters of Abu Qir Bay. It is likely that some combination of these natural phenomena was responsible for their rapid demise more than 1200 years ago. Geologists and archaeologists have reconstructed a scenario of disaster rather than one of gradual subsidence of the cities. Remains found under the Mediterranean indicate that Menouthis was abandoned rapidly, apparently in response to liquefaction of the silt-rich delta sediments. What is less clear is the cause of the sudden transformation of the ground into muddy liquid. One interpretation is that a powerful earthquake shook the area. A second interpretation is that one or more unusually strong Nile floods caused the damage. The date of the destruction is reasonably well-constrained. Arabic coins found at the site date from 724 and 740 AD, indicating the cities were functioning centers of trade at that time. Canopus is also mentioned in contemporary writings by travelers of that same era. Previous work in the Middle East documented a strong (magnitude 7.0 to 7.3) earthquake along the Dead Sea transform fault in 749 A.D.

that affected large portions of the region (can you locate the Dead Sea transform?). As residents of San Francisco know all too well, soil liquefaction is both common and treacherous during an earthquake and could easily account for the soil failures observed in the ancient delta. Archaeological investigations have found temple columns aligned parallel to one another under the water, a configuration often associated with earthquake damage. Written records also indicate anomalously high Nile floods in 741-742 AD. The rushing floodwaters could also have overwhelmed the distributary and caused the sediments to become water-laden. In addition, floods often cause rivers to relocate to new courses, and the Canopus distributary may have abandoned its banks following the flooding. It may well be that both disasters took place, and that the resulting decade of physical instability led to the ultimate and final demise of the two cities. This field displays text for the image slideshow. The truth is that these two cities would have eventually disappeared even without one or more natural disasters. The Nile delta - any delta - subsides over time as water is pushed out from between individual sediment grains during compaction.

The following time-line shows the likely sequence of events, both gradual and catastrophic, that led to the ultimate demise of Canopus and Herakleion. As you look at the image, think about the future of New Orleans. Timeline for geologic processes at Abu Qir sites. Source: Submergence of Ancient Greek Cities Off Egypt's Nile Delta — A Cautionary Tale Let's look at one more example of an amazing piece of history that was lost under the waters of the Mediterranean near the mouth of the Nile. The "slide show" below shows a map of the Seven Wonders of the Ancient World (Image 1) and a modern map (Image 2) that shows the Seven Wonders in a more modern configuration. This field displays text for the image slideshow. Remember that the Seven Wonders, which were catalogued in the 5th Century BC by Herodotus, reflect only those portions of the world known to the ancient Greeks. Other remarkable feats of human construction, including the Great Wall of China, were likely unknown to Herodotus. One of the Seven Wonders was the Pharos, or Lighthouse, of Alexandria (see "slideshow" below).

The remarkable city of Alexandria (an intellectual and scientific capital of the contemporary world) was founded in 332 BC by the Macedonian conqueror Alexander the Great. Alexander died shortly thereafter (in 323 BC), and the city was completed by Ptolemy Soter, the new ruler of Egypt. Alexandria quickly became a wealthy city as it oversaw activity of trade ships that sailed across the Mediterranean. This field displays text for the image slideshow. Ptolemy authorized construction of the Pharos in 290 BC. It was the first lighthouse in the world, and served as both a symbol of the city as well as a safe guide for shipping in and out of the busy harbor for some 1600 years. When the Lighthouse was completed, about 20 years later, it was the tallest building other than the Great Pyramid. The configuration of the harbor made it dangerous, and so the lighthouse was constructed on Pharos Island (see map below). Several contemporary descriptions of the Pharos - including those by Pliny the Elder - enable us to envision the building as it was in its prime.

These descriptions tell how the mirror could reflect light from tens of kilometers away, and how the mirror (perhaps an early telescope) was used to detect enemy ships before they sailed towards the harbor. A statue of Poseidon stood at the top of the tower. Pharos. Source: Where is the Pharos now? A series of earthquakes between the 4th and 14th Centuries AD gradually destroyed the lighthouse; its final collapse came in 1326 AD. Some archaeologists believe the ruins of the Pharos lie in the harbor near modern Fort Qaitbey. You can learn about the excavation of the lighthouse at . Drainage basin | WaterWiki | Fandom powered by Wikia Edit Drainage basins of the major oceans and seas of the world. Grey areas are endorheic basins that do not drain to the ocean. The Atlantic Ocean drains approximately 47% of all land in the world. In North America, it directly drains the Saint Lawrence River and Great Lakes basins, the Eastern Seaboard of the United States, the Canadian Maritimes , and Newfoundland and Labrador .

It also directly drains nearly all of South America (that portion east of the Andes ), northern Europe , and the greatest portion of western Sub-Saharan Africa . The the three major mediterranean seas of the world also flow to the Atlantic: The basin of the American Mediterranean Sea (the Caribbean Sea and Gulf of Mexico ) includes all of the American interior between the Appalachian and Rocky mountains, eastern Central America , and a small part of northern South America . The basin of the European Mediterranean Sea includes much of northeastern Africa (including Egypt , Libya , Sudan and the other countries of the Nile basin), southern and eastern Europe, Turkey , and the coastal areas of Israel, Lebanon, and Syria. The basin of the Arctic Sea drains most of northern Canada and Russia . The Pacific Ocean drains just over 13% of the land in the world. Its basin includes much of China , southeastern Russia , Japan , Korea , most of Indonesia and Malaysia , the Philippines , all Pacific Islands , the northeast coast of Australia, most of Alaska , the western part of Canada, the United States, Central America, and the South America (the smaller portion west of the Andes ). The Indian Ocean drains around 13% of the Earth's land.

It drains the eastern coast of Africa, the coasts of the Red Sea and the Persian Gulf , the Indian subcontinent , Burma , and most of Australia . The Southern Ocean drains Antarctica . (At least those portions that drain; there is no runoff from the interior of the continent.) Antarctica comprises approximately 8% of the Earth's land. Endorheic drainage basins Edit Endorheic drainage basins are inland basins that do not drain into an ocean; around 18% of all land drains to endorheic lakes or seas. The largest of these consists of much of the interior of Asia , and drains into the Caspian Sea and the Aral Sea . Other basins include the Great Basin in the United States , much of the Sahara Desert , the watershed of the Okavango River ( Kalahari Basin ), highlands near the African Great Lakes , the interiors of Australia and the Arabian Peninsula , and parts in Mexico and the Andes . Geopolitical boundaries Edit Drainage basins have been important historically in determining boundaries, particularly in regions where trade by water has been important.

For example, the English crown gave the Hudson's Bay Company a monopoly on the Indian Trade in the entire Hudson Bay watershed, an area called Rupert's Land. The company later acquired the North American watershed of the Arctic Ocean (the North-Western Territory ). These lands later became part of Canada as the Northwest Territories , making up the vast majority of Canada's land area. Today, bioregional democracy can include agreements of states in a particular drainage basin to defend it. These include the Great Lakes Commission . Hydrology File:Ohiorivermap.png The largest drainage basin in the world is the Amazon , covering 6,144,727 km² (a third of the area of South America). In hydrology , the drainage basin is a logical unit of focus for studying the movement of water within the hydrological cycle , because the majority of water that discharges from the basin outlet originated as precipitation falling on the basin. A portion of the water that enters the groundwater system beneath the drainage basin may flow towards the outlet of another drainage basin because groundwater flow directions do not always match those of their overlying drainage network. Measurement of the discharge of water from a basin may be made by a stream gauge located at the basin's outlet.

Rain gauge data is used to measure total precipitation over a drainage basin, and there are different ways to interpret that data. If the gauges are many and evenly distributed over an area of uniform precipitation , using the arithmetic mean method will give good results. In the Thiessen polygon method , the watershed is divided into polygons with the rain gauge in the middle of each polygon assumed to be representative for the rainfall on the area of land included in its polygon. These polygons are made by drawing lines between gauges, then making perpendicular bisectors of those lines form the polygons. The isohyetal method involves contours of equal precipitation are drawn over the gauges on a map. Calculating the area between these curves and adding up the volume of water is time consuming. Ecology File:Mississippi River basin.jpg Drainage basins are important elements to consider also in ecology . As water flows over the ground and along rivers it can pick up nutrients, sediment, and pollutants . Like the water, they get transported towards the outlet of the basin, and can affect the ecological processes along the way as well as in the receiving water body. Modern usage of artificial fertilizers, containing nitrogen, phosphorous, and potassium, has affected the mouths of watersheds.

The minerals will be carried by the watershed to the mouth and accumulate there, disturbing the natural mineral balance. Resource management Edit Because drainage basins are coherent entities in a hydrological sense, it has become common to manage water resources on the basis of individual basins. In Minnesota, U.S.A., governmental entities that perform this function are called watershed districts . In New Zealand, they are called catchment boards. Comparable community groups based in Ontario, Canada, are called conservation authorities . In North America this function is referred to as watershed management . In Brazil , the National Policy of Water Resources, regulated by Act n° 9.433 of 1997, establishes the drainage basin as territorial division of Brazilian water management.

Question: Into what body of water does the Nile River drain?
Answer: The Mediterranean Sea